Digital display mechanism for a time-keeper

ABSTRACT

The invention concerns a click mechanism for a clock or calendar, having two indicating or number discs but only one click or detent spring, thus reducing the friction in, and the driving force required by, the mechanism. The units disc has a click wheel and spring, and is driven step-by-step by known means. When the figure 0 enters a display opening, the units disc turns a spur wheel which drives a second spur wheel attached to the tens disc, through a limited angular distance. The drive is completed by a lever driven by the completion of the step of the units disc, the lever locking the tens disc until the next time the disc is to be stepped.

[ June 25, 1974 DIGITAL DISPLAY MECHANISM FOR A TIME-KEEPER [75] lnventor: Jacques Miiller, Reconvilier, Switzerland [73] Assignee: Ebauches Tavannes S.A., Berne,

Switzerland [22] Filed: Nov. 19, 1973 [21] Appl. No.: 416,837

[30] Foreign Application Priority Data Dec. 6, 1972 Switzerland 17742/72 [52] US. Cl. 58/5, 58/58, 58/125 B [51] Int. Cl G04b 19/24, G04b 19/02 [58] Field of Search 58/4, 5, 58, 125 B [56] References Cited UNITED STATES PATENTS 2,579,166 12/1951 Youhouse 58/125 B X 2,976,672 3/1961 Ducommun 58/5 X FOREIGN PATENTS OR APPLICATIONS 1,186,707 8/1959 France 58/125 B Primary Examiner-Richard B. Wilkenson Assistant Examiner-Edith Simmons Jackmon I QH QJKMQ! FWzQWBhtkis ils "Hide and Smiley 5 7] ABSTRACT The invention concerns a click mechanism for a clock or calendar, having two indicating or number discs but only one click or detent spring, thus reducing the friction in, and the driving force required by, the mechanism. The units disc has a click wheel and spring, and is driven step-by-step by known means. When the figure 0 enters a display opening, the units disc turns a spur wheel which drives a second spur wheel attached to the tens disc, through a limited angular distance. The drive is completed by a lever driven by the completion of the step of the units disc, the lever locking the tens disc until the next time the disc is to be stepped.

8 Claims, 4 Drawing Figures PATENfEnJuuzsmq SHEET 1 [IF 2 1 DIGITAL DISPLAY MECHANISM FOR A TIME-KEEPER The present invention has for its subject a digital display mechanism for a time-keeper comprising a units disc placed concentrically with respect to a tens disc.

In a known digital'display mechanism two discs are provided, one indicating tens of minutes and one units; these discs are placed concentrically with respect to one other, and both are provided with a click as detent spring, which introduce fairly large friction forces in the movement.

The object of the present invention is to provide a digital display mechanism with two discs but only one click element, thus reducing friction forces and simplifying the construction.

According to the present invention there is therefore provided a digital display mechanism for a time-keeper, comprising a units disc, at tens disc placed concentrically therewith, said units disc having a finger initially driving a wheel drivingly co-operating with a tens star wheel, and a lever having inclined faces co-operating with said star wheel to effect a final driving action on said tens star wheel after the action of said finger, under the control of said units disc.

The accompanying drawings illustrate one embodiment of a device in accordance with the invention; in the drawings,

FIG. 1 is a plan view of a digital display mechanism before rotation of the tens disc,

FIG. 2 is a plan view showing a digital display mechanism during the operation of rotation of the tens disc,

FIG. 3 is a plan view, similar to FIG. 1, after rotation of the tens disc, and

FIG. 4 is a cross-section of the digital display mechanism.

Referring to FIGS. 1 and 4, it will be seen that the mechanism comprises a units disc 1 provided with a locking device 2 including a star wheel 3 having teeth, integrally mounted on the units disc I. The wheel 3 is positioned by means of a click spring or detent 4. The units disc 1 pivots freely on a ring 7 turned in a bottom plate 8, and provided with a finger 9 which cooperates with a driving pinion I0 freely mounted on a shoulder 11 of a headed pin 12 pressed into a hole 13 in the bottom plate 8. 1

The pin 11 also carries a freely pivoted lever 14 with inclined surfaces 15 and 16 and a nose l7 able to penetrate into a notch 19 machined on the inner face of the units disc 1. The notch 19 has an entry slope 20 and a retaining edge 21.

The pinion l0 co-operates with a tens star wheel 24 with six teeth which freely pivots on a collet 25 fixed to the bottom plate 8. The tens star wheel 24 presents on one of its lateral sides a counter-sunk portion receiving a tens disc 26 placed concentrically with respect to the units disc 1.

The tens star wheel 24 is normally held stationary by the inclined surfaces 15 and 16 of lever 14 which protrude between the flanks 28 and 29 of teeth 31 and 31 respectively of the star wheel 24, the lever being held by the nose l7'which normally abuts against the inner surface 30, when the units disc I is in rotation.

The tens star wheel 24 is maintained in place by means of a fixing screw 32. The units disc is positioned 2 in its axial direction by the ring 7 and by a plate 33 fixed to the plate 8 by means of a screw 34.

The operation of the mechanism will now be described referring to FIGS. 1, 2 and 3. The units disc 1 is numbered 0 to 9 and is entrained step-by-step one per minute by known means (not described), the appropriate number being presented in a window 37 of a casing 38. As shown in FIG. 1, the units disc 1 is caused by contact with the finger 9 to operate the intermediate pinion 10; however, as the notch 19 does not yet correspond with the position of the nose 17, the inclined planes l5 and 16 hold the tens star wheel 24 preventing the changing of the tens digit.

In FIG. 2 the unfinished jump of the units disc 1, exerts a force by means of the finger 9 on the intermediate pinion 10 which entrains in turn the tens star wheel 24, which itself pushes back the lever 14 the nose 17 of which has dropped into the notch 19 machined in the units disc 1.

Since the finger 9 is now disengaged from the intermediate pinion 10, completion of the rotation of the tens star wheel 24 is effected by means of the lever 14 the nose 17 of which is pushed towards the centre of the units disc 1 by the slope 20, thus producing the completion of a rotary stop of the tens star wheel 24 and of the tens disc 26 by meshing of the surface 15 with the flanks 28 of the teeth 31, 31'.

In FIG. 3, the nose 17 of the lever 14 again rests against the inner periphery 30 of the units disc 1, and remains so until the finger 9 has run around one complete turn relative to the indication of the numbers 0 to 9. It is clear that the tens star wheel 24 is locked by the inclined planes 15 and 16 during the indication of unit numbers 1 to 9.

It is possible to use the same mechanical system as described above for a perpetual calender having a window with a units disc and a tens, disc. The tens star wheel would have eight teeth instead of ten teeth as in the mechanism described. A rapid correction of the date indication is feasible at the end of each month from the indication 29, 30 or 31 by rotation of units disc 1 by approximately one revolution by means of a winding crown in order to advance the display to cipher 1.

We claim:

1. A digital display mechanism for a time-keeper, comprising a units disc, a tens disc placed concentrically therewith, said units disc having a finger initially driving a wheel drivingly co-operating with a tens star wheel, and a lever having inclined faces co-operating with said star wheel to effect a final driving action on said tens star wheel after the action of said finger, under the control of said units disc.

2. A mechanism as recited in claim 1 characterized in that said lever is provided with a nose which abuts against the inner periphery of said units disc during the display of the units digits 1 to 9, thus locking said tens star wheel by means of said inclined faces.

3. A mechanism as recited in claim 1 characterized in that said lever nose is adapted to enter a notch which during rotation of said units disc causes said lever to exert a turning movement on said tens star wheel by the means of one of said inclined faces.

4. A mechanism as recited in claim 3 characterized in that said finger effects a couple on said wheel which co-operates with said tens star wheel to push back said lever by means of an inclined face of said notch.

in that said tens disc indicates tens of minutes and said units disc indicates individual minutes.

8. A mechanism as recited in claim 6, characterised in that said tens and units disc indicate a date. 

1. A digital display mechanism for a time-keeper, comprising a units disc, a tens disc placed concentrically therewith, said units disc having a finger initially driving a wheel drivingly co-operating with a tens star wheel, and a lever having inclined faces co-operating with said star wheel to effect a final driving action on said tens star wheel after the action of said finger, under the control of said units disc.
 2. A mechanism as recited in claim 1 characterized in that said lever is provided with a nose which abuts against the inner periphery of said units disc during the display of the units digits 1 to 9, thus locking said tens star wheel by means of said inclined faces.
 3. A mechanism as recited in claim 1 characterized in that said lever nose is adapted to enter a notch which during rotation of said units disc causes said lever to exert a turning movement on said tens star wheel by the means of one of said inclined faces.
 4. A mechanism as recited in claim 3 characterized in that said finger effects a couple on said wheel which co-operates with said tens star wheel to push back said lever by means of an inclined face of said notch.
 5. A mechanism as recited in claim 1 characterized in that said tens star wheel comprises six teeth.
 6. A mechanism as recited in claim 1 characterized in that said tens star wheel comprises eight teeth.
 7. A mechanism as recited in claim 5 characterized in that said tens disc indicates tenS of minutes and said units disc indicates individual minutes.
 8. A mechanism as recited in claim 6, characterised in that said tens and units disc indicate a date. 